ASHP - how noisy are they in reality

[Walshie]

Hi,

Would appreciate any thoughts on ASHP's and noise?

The ideal location would be at the side of the house but this borders our neighbours.

Do I need to be concerned about noise potentially being an issue for us and our neighbours.

Luckily, the neighbours are great and so keen not to hack them off more than we have to.

 

Any advice gratefully received!

Thx

 

[Chanmenie]

Depends on the heat pump I think.

I can honestly say my Veismann Vitocal is very quiet, I can stand right next to it and not know it’s running other than by the cold air coming from the fan.

other people have also remarked on how quiet it is. 
It faces my neighbour and is 6 meters from the boundary, his oil fired boiler is considerably more noisy, he has never heard my heat pump running. 

[nod]

Our Mitsubishi eco Was very quiet when first installed You couldn’t hear it from 3 meters away 

After about a month You can hear the fan from about 10 meters away 

[scottishjohn]

I have Samsung at new house-- 16kw unit and depending on how hard it works it is near silent to  acceptably loud as its outside 

[sharpener]

Vaillant twin fan (12kW) facing next door, neighbour cannot hear it and it is near silent at up to 85% output, above that there is a slight buzz but you wouldn't want to be outside for long when it is that cold.

[Conor]

Our cool energy 9kw isn't any louder than a large office fan. The only time it's noisier is when on cooling mode, when it sounds like an overboiling saucepan on a stove. But that's like 5 days a year.

[nod]

  On 02/04/2025 at 18:18, Conor said:

Our cool energy 9kw isn't any louder than a large office fan. The only time it's noisier is when on cooling mode, when it sounds like an overboiling saucepan on a stove. But that's like 5 days a year.

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Exactly 

Its a large fan 

[Conor]

  On 02/04/2025 at 18:26, nod said:

Exactly 

Its a large fan 

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I know?! Some people think they sound like a motorway at rush hour or flight EZY665 on takeoff.

[ReedRichards]

They are typically no more noisy that the flue from a condensing boiler but they are subject to restrictions on noise, unlike boilers.

[JoeBano]

My extractor fan in the downstairs toilet is louder than my grant aerona3 unless it’s doing a hot water cycle the compressor noise is louder.

[JamesP]

The mechanical noise of our ASHP is minimal  but the movement of air does create a quite a loud hum and the force of the fan is strong.

Personally, I would not position the pump facing neighbours though depends on distance etc.

Hopefully @SteamyTea will be along to explain about air particles colliding.

 

[Nickfromwales]

Last 2 Panasonics I fitted were virtually inaudible tbf, and the 2 Stiebel Eltrons we did even more so. Design is paramount so these aren't running flat out, ever, so measure twice install once (and nice & quietly!).

 

1x S.E. client could hear the neighbours combi flue (30m away) over the unit on full chat, when heating the house for the first time and stood right next to it. 1x Panasonic client had his backing on to the neighbours waffle fence (dwarf one) and on test the neighbour asked the client if they'd hear the unit....he said "It's going full chat right now!".....she said "I can't hear it".....client replied "yup!". Happy days.

 

There are cheap nasty ASHP's out there, and instances where they should not have been installed, so these are out there as poor examples which people fear. Minds are changing with each 'better' install, just gonna take time I guess.

[SteamyTea]

  On 02/04/2025 at 20:53, JamesP said:

Hopefully @SteamyTea will be along to explain about air particles colliding.

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I am staying silent on this one.

[Beau]

We have the Vaillant aroTHERM plus 7kW. Its not bad but a bit noisy when working hard. Also get an annoying resonance at times. If I press against the case it stops but haven't yet been able to trace the cause. The sound of the water flowing around the rads is quite intrusive especially on the first few rads in the system. I say all this but having gone from no heating system it was always going to be different and we live remotely so dont have any background noise to mask the noise the system makes.

[SteamyTea]

  On 03/04/2025 at 08:53, Beau said:

bit noisy when working hard. Also get an annoying resonance at times. If I press against the case it stops but haven't yet been able to trace the cause. The sound of the water flowing around the rads is quite intrusive especially on the first few rads in the system

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Sounds to me as if it is not set up right.

What are the flow temperatures and rates?

[Nickfromwales]

Yup, sounds like the pump is on full wallop and hasn’t been commissioned to dial it back to a lower speed setting. 

[Beau]

  On 03/04/2025 at 09:25, SteamyTea said:

Sounds to me as if it is not set up right.

What are the flow temperatures and rates?

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Thanks SteamyTea

 

Right now flow temp is down at 25c for an inside temp of 18C but the rads are still noisy. Its set up to only run from weather comp. Highest flow I have seen is 38C but I dont check it very often and dont yet have an app to easily see whats happening. No idea what the flow rates are as not sure where to find that info

[JamesPa]

Vaillant 7kW here, double glazed living room window just 30cm from the unit and adjacent utility room window immediately behind the unit.

 

Most of the time its totally silent indoors and whisper quiet outdoors, inaudible from >3-4m away. 

 

When it working really hard, which it does for typically 5-10 minutes after a defrost at - temperatures and very occasionally for longer periods up to say 30mins, its just audible indoors, but still quieter than the fridge in the same room and quieter than the gas flue was in the bathroom to which the flue was adjacent.  Outdoors in this relatively rare situation there is a buzz which seems to appear at compressor modulation >80%.  I've turned on noise reduction mode at night out of respect for the neighbours, however I only did this about a month in and after some quite severe defrosts, and they now tell me that they didn't even know I had the heat pump!  Their bedroom window is about 6m away, albeit screened by the building. 

 

No noise from pipework, which is odd because there was pipework noise with the gas boiler when it was heating DHW.

 

Overall, for me. no more of a problem than a gas boiler.  

[Chanmenie]

  On 03/04/2025 at 11:18, Beau said:

Thanks SteamyTea

 

Right now flow temp is down at 25c for an inside temp of 18C but the rads are still noisy. Its set up to only run from weather comp. Highest flow I have seen is 38C but I dont check it very often and dont yet have an app to easily see whats happening. No idea what the flow rates are as not sure where to find that info

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Crikey, is it cold where you are ? mines been turned off for 3 weeks and the internal temp hasn’t gone below 19.7 it was 23 this afternoon 

[marshian]

  On 03/04/2025 at 20:54, Chanmenie said:

Crikey, is it cold where you are ? mines been turned off for 3 weeks and the internal temp hasn’t gone below 19.7 it was 23 this afternoon 

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houses are different - I won’t turn my heating off until mid may normally 

 

 

[JohnMo]

  On 03/04/2025 at 20:59, marshian said:

houses are different - I won’t turn my heating off until mid may normally 

 

 

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Yep, we still get best part of zero at night. Heating could go off, every few days, but it's free from excess PV, so why bother switching it off.  

 

Mine generally is heating, then cooling until September. Not much middle ground.

[Beau]

  On 03/04/2025 at 20:54, Chanmenie said:

Crikey, is it cold where you are ? mines been turned off for 3 weeks and the internal temp hasn’t gone below 19.7 it was 23 this afternoon 

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We live on Dartmoor. It's around 11C outside and been gusting 55 kmh. The house is only part renovated and we get poor solar gain due to having just two south facing windows and are very shaded from the east. 

Edited Thursday at 21:09 by Beau

[marshian]

  On 03/04/2025 at 08:53, Beau said:

We have the Vaillant aroTHERM plus 7kW. Its not bad but a bit noisy when working hard. Also get an annoying resonance at times. If I press against the case it stops but haven't yet been able to trace the cause. The sound of the water flowing around the rads is quite intrusive especially on the first few rads in the system. I say all this but having gone from no heating system it was always going to be different and we live remotely so dont have any background noise to mask the noise the system makes.

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OK I don't have ASHP I have a Gas Boiler basically running ASHP flow temps. All rads no UFH.

 

My pet hate is system noise (flow thro the rads) I've gone to a lot of effort to get the flow rates right for each individual room based on the target room temp - I don't run any set backs - heating is on 24/7. I am running a with weather compensated flow temp but it's been well worth the time invested in getting every room right. Highest flow temp I've seen over winter was 35 deg C. Right now the boiler is targeting 22 Deg Flow temp.

 

Sitting in my living room right now all I can hear is the wall clock ticking no system noise at all.

 

I think if your circuit is noisy you might have a little too much flow thro it.

 

 

[Beau]

  On 03/04/2025 at 23:03, marshian said:

 

 

Sitting in my living room right now all I can hear is the wall clock ticking no system noise at all.

 

I think if your circuit is noisy you might have a little too much flow thro it.

 

 

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I suspect your right but not sure what to do about it. This morning I came down and it was just audible like say a gas boiler in a neighbouring room. Now it's just stepped up more like I am in the room with a boiler even though is not cold outside and flow temps are low. Sometimes when its cold you get a two noises one is just rushing water in pipes but there is a second like a distant car is coming up our quiet country road but never gets here. I think the second noise is the heat pump running getting carried through the pipes. It's interesting that others say their systems are near silent as I had just put it down to the ASHPs needing high flow rates but maybe this is not the case. I did mention it early on to the installer but they just shrugged as though it was normal. On the water noise in the pipes I dont think I saw them deburr inside any of the pipes it was just pipe cutter then clamp. Could the burrs be causing turbulence and in turn the noise of rushing water?

[SteamyTea]

  On 03/04/2025 at 20:59, marshian said:

  On 03/04/2025 at 20:54, Chanmenie said:

Crikey, is it cold where you are ? mines been turned off for 3 weeks and the internal temp hasn’t gone below 19.7 it was 23 this afternoon 

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houses are different - I won’t turn my heating off until mid may normally 

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Not just houses, regional weather makes a difference.

Down here, our local temperatures are predominately governed by sea surface temperature.